The good new, is that an other user reported it as working, not using a PS4 or such a high video bitrate as your samples though.

I did make a more optimized version, that should give you suffisant speed to be able to stream it in real time, and changed the output specifications, as we are in the dark on what kind of MP4 the PS4 support until you test the 2 files on USB, HDD or DVD / BD whatever.

So, let's cross fingers

https://we.tl/cvOn2b6kbT
Btw, i saw that you play them from the #--TRANSCODE--# folder. Could you play then normally, without going through that folder ?

EDIT 2: Sorry, i've forgotten your question...
No thumbnail could come from the fact that the old FFmpeg version do not support well HEVC, though you should have the default thumbnail, or that the 4 seconds predefined, that you can change from the GUI, is on the black part of the video and you get only black as expected. In such case upgrading FFmpeg or changing the delay (10 s or more) could solve your thumbnails issue.
Anyway, if you still get thumbnails issue, you should open a new issue only for that, @Nadahar is the one "assigned" to this.

looool noooo. It's not about the thumbnail. The thumbnails are perfect but it's about the video. When I start playing the videos, my screen remains black with the "triangle, cross, square, circle" moving. And in the end: it tells me unreadable media.

For the usb unfortunately it doesn't work... snif, snif I have to buy a ps4 compatible usb stick.